On two occasions over the past two years tests on brickwork have been carried out at the University of Surrey. One aspect of this work was a series of compressive tests on common brickwork and 1 : 1 : 6 mortar. . The aim was to produce in the laboratory brickwork similar to that produced on site.15. The relative bulk densities of materials for the mortar were found by filling, without compaction, a container with a volume of approximately 0.01 m3. The sand used in the test was wet, so that bulking occurred (see Table 4). In these tests the sand/cement ratio was up to 36% higher than that given in BS 4551, Part 1 . The grading curve for the sand used in the first tests was entered between the limits specified in BS 1200, 1955. In the second test the curve was just below the fine limit (Fig. 4). Water was added to each mix to give a workable consistency that satisfied the bricklayer.16. Cubes were taken at regular intervals as the main walls were being built, the mortar being tamped lightly into the mould. These cubes were cured in the moulds for two days with a covering of polythene, and then left in the laboratory until they were tested between 28 and 35 days later.17. The compressive strengths compared with the water/cement ratio varied with the test. However they were of the same order as that given in the Note (Table 5 and Fig. 5).18. There are two points that have come up in this work. The first is that it would help quality control if CP 111 would lay down guidelines on weigh batching. The second concerns the water/cement ratio. Where porous bricks/blocks are being used, the water can be sucked out of the mortar; this can lead to improved strengths if the mortar is tamped down as the bricks/blocks are laid. There can be a weakening of the mortar due to porosity associated with the suction. 19. Finally, on these tests, 215 mm X 215 mm columns, 12 courses high with plain
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.